Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and its incidence is gradually increasing in Japan as well as in United States (Akriviadis E A, et al., Br J. Surg. 1998 October; 85(10):1319-31). Although recent medical advances have made great progress in diagnosis, a large number of patients with HCCs are still diagnosed at advanced stages and their complete cures from the disease remain difficult. In addition, patients with hepatic cirrhosis or chronic hepatitis have a high risk to HCCs, they may develop multiple liver tumors, or new tumors even after complete removal of initial tumors. Therefore development of highly effective chemotherapeutic drugs and preventive strategies are matters of pressing concern.
Colorectal carcinoma is a leading cause of cancer deaths in developed countries. Specifically, more than 130,000 new cases of colorectal cancer in the United States are reported each year. Colorectal cancer represents about 15% of all cancers. Of these, approximately 5% are directly related to inherited genetic defects. Many patients have a diagnosis of pre-cancerous colon or rectal polyps before the onset of cancer. While many small colorectal polyps are benign, some types may progress to cancer. The most widely used screening test for colorectal cancer is colonoscopy. This method is used to visualize a suspicious growth and/or take a tissue biopsy. Typically, the tissue biopsy is histologically examined and a diagnosis delivered based on the microscopic appearance of the biopsied cells. However, this method is limited in that it yields subjective results and can not be used for very early detection of pre-cancerous states. The development of a sensitive, specific and convenient diagnostic system for detecting very early-stage colorectal cancers or pre-malignant lesions is highly desirable as it could ultimately eliminate this disease.